#include <stdio.h>
#include <unistd.h>

int main()
{
  pid_t id = fork();
  if(id<0)
  {
    printf("fork error\n");
    return 1;
  }
  else if(id==0)
  {
    printf("我是子进程,pid:%d,ppid:%d\n",getpid(),getppid());
    int* addr = NULL;
    *addr = 100;
  }
  else
  {
    while(1)
    {
      printf("我是父进程,pid:%d,pid:%d\n",getpid(),getppid());
      sleep(1);
    }
  }
  return 0;
}
